Method and user equipment for handling service connectivity in wireless communication system

ABSTRACT

A method for handling a service connection in a wireless communication system, including detecting, by a User Equipment (UE), a Mobility Management (MM) service state of the UE is set to ATTEMPTING TO UPDATE, receiving, by the UE, a valid Temporary Mobile Subscriber Identity (TMSI) in a TMSI reallocation procedure from a base station via a Radio Resource Control (RRC) connection, changing, by the UE, the MM service state to a NORMAL SERVICE state in response to the receiving a valid TMSI and the detecting a MM service state, and sending, by the UE, a paging response message to the base station in response to the changing the MM service state and a paging indication message received from the base station to establish the service connection, the paging indication message including the valid TMSI.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 16/595,638, filed on Oct. 8, 2019, which claims priority to IndianProvisional Patent Application No. 201841038035 filed on Oct. 8, 2018 inthe Indian Intellectual Property Office, and Indian Patent ApplicationNo. 201841038035 filed on Oct. 7, 2019 in the Indian IntellectualProperty Office, the disclosure of each which is incorporated byreference herein in its entirety.

BACKGROUND

The present disclosure relates to a wireless communication system, andmore specifically related to a method and User Equipment (UE) forhandling service connectivity in the wireless communication system.

According to 3rd Generation Partnership Project (3GPP) specification24.008, when the Mobility Management (MM) Service state of a UserEquipment (UE) in a Global System for Mobile communication (GSM) orUniversal Mobile Telecommunications Service (UMTS) Radio AccessTechnology (RAT) has entered into an ATTEMPTING TO UPDATE state duringwhich the T3211 timer runs, the UE does not respond to a received pagingmessage including a Temporary Mobile Subscriber Identity (TMSI).Instead, in the ATTEMPTING TO UPDATE MM Service state, the UE respondsto the received paging message when the paging message includes anInternational Mobile Subscriber Identity (IMSI).

In such case (e.g., when responding to the received paging message withthe IMSI), when a paging response message is triggered, the T3211 timer(which is running) stops. A Radio Resource Control (RRC) connection isestablished with a base station for performing TMSI RE-ALLOCATION. Forexample, the UE receives a new TMSI from the base station and stores thenew TMSI. Connection management (CM) layer procedures corresponding tothe received paging message are completed and connection (e.g., a RadioResource Control (RRC) connection with a base station) release isperformed. While the MM Service state of the UE remains in an ATTEMPTINGTO UPDATE state, the UE waits for T3212 expiry or the UE waits forchange of location area (LA) to trigger the location update procedure tothe base station.

SUMMARY

Some example embodiments provide a method for handling a serviceconnectivity in a wireless communication system.

Some example embodiments provide for detecting that a UE is in a MMservice state attempting to update.

Some example embodiments provide for receiving a valid TMSI in a TMSIreallocation procedure when the UE exists a Radio Resource Control (RRC)connection.

Some example embodiments provide for changing the MM service state to aNORMAL SERVICE state based on the TMSI reallocation procedure.

Some example embodiments provide for changing an update status to U1UPDATED.

Some example embodiments provide for performing a location updatingprocedure on a RRC connection release to indicate that a TMSIreallocation procedure is not performed to a base station in response toreceiving the paging message with the IMSI, when the timer is running.

Some example embodiments provide a method for handling a serviceconnection in a wireless communication system. The method includesdetecting, by a User Equipment (UE), a Mobility Management (MM) servicestate of the UE is set to ATTEMPTING TO UPDATE, receiving, by the UE, avalid Temporary Mobile Subscriber Identity (TMSI) in a TMSI reallocationprocedure from a base station via a Radio Resource Control (RRC)connection, changing, by the UE, the MM service state to a NORMALSERVICE state in response to the receiving a valid TMSI and thedetecting a MM service state, and sending, by the UE, a paging responsemessage to the base station in response to the changing the MM servicestate and a paging indication message received from the base station toestablish the service connection, the paging indication messageincluding the valid TMSI.

In some example embodiments, further, the method includes changing, bythe UE, an update status of the UE to U1 UPDATED in response to thereceiving a valid TMSI.

In some example embodiments, the service connection is at least one of acall connection, a Short Message Service (SMS) connection or asupplementary service (SS) connection.

Some example embodiments provide a method for handling a serviceconnection in a wireless communication system. The method includesdetecting, by a User Equipment (UE), a Mobility Management (MM) servicestate of the UE is set to ATTEMPTING TO UPDATE, receiving, by the UE, apaging message including an International Mobile Subscriber Identity(IMSI), determining, by the UE, whether a timer is running, performing,by the UE, a location area updating procedure with a base station inresponse to the detecting a MM service state, the determining the timeris running, and releasing a Radio Resource Control (RRC) connection withthe base station associated with the paging message, and establishingthe service connection with the base station using a valid TemporaryMobile Subscriber Identity (TMSI) obtained during the location areaupdating procedure.

Some example embodiments provide a UE for handling a service connectionin a wireless communication system. The UE includes processing circuitryconfigured to detect a Mobility Management (MM) service state of the UEis set to ATTEMPTING TO UPDATE, receive a valid Temporary MobileSubscriber Identity (TMSI) in a TMSI reallocation procedure from a basestation via a Radio Resource Control (RRC) connection, change the MMservice state to a NORMAL SERVICE state in response to receiving thevalid TMSI and detecting the MM service state is set to ATTEMPTING TOUPDATE, and send a paging response message to the base station inresponse to changing the MM service state to the NORMAL SERVICE stateand a paging indication message received from the base station toestablish the service connection, the paging indication messageincluding the valid TMSI.

Some example embodiments provide a UE for handling a service connectionin a wireless communication system. The UE includes processing circuitryconfigured to detect a Mobility Management (MM) service state of the UEis set to ATTEMPTING TO UPDATE, receive a paging message including anInternational Mobile Subscriber Identity (IMSI), determine whether atimer is running, perform a location area updating procedure with a basestation in response to detecting the MM service state is set toATTEMPTING TO UPDATE, determining the timer is running, and releasing aRadio Resource Control (RRC) connection with the base station associatedwith the paging message, and establish the service connection with thebase station using a valid Temporary Mobile Subscriber Identity (TMSI)obtained during the location area update procedure.

These and other aspects of some example embodiments herein will bebetter appreciated and understood when considered in conjunction withthe following description and the accompanying drawings. It should beunderstood, however, that the following descriptions, while indicatingsome example embodiments and numerous specific details thereof, aregiven by way of illustration and not of limitation. Many changes andmodifications may be made within the scope of some example embodimentsherein without departing from the spirit thereof, and some exampleembodiments herein include all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments are illustrated in the accompanying drawings,throughout which like reference letters indicate corresponding parts inthe various figures. Some example embodiments herein will be betterunderstood from the following description with reference to thedrawings, in which:

FIG. 1a illustrates an overview of a wireless communication system forhandling a service connectivity, according to some example embodiments;

FIG. 1b illustrates various hardware components of the UE, according tosome example embodiments;

FIG. 1c illustrates various hardware components of a processor,according to some example embodiments;

FIG. 2 is a flow diagram illustrating a method for handling the serviceconnectivity in the wireless communication system, when the UE was inthe ATTEMPTING TO UPDATE MM service state, and receives the valid TMSIin the TMSI reallocation procedure when the RRC connection exists,according to some example embodiments;

FIG. 3 is a flow diagram illustrating a method for handling the serviceconnectivity in the wireless communication system, when the UE was inthe ATTEMPTING TO UPDATE MM service state, and receives the pagingmessage with IMSI when the timer T3211, T3213, and/or T3246 is running,according to some example embodiments;

FIG. 4 is an example sequence flow diagram illustrating operations forhandling the call connectivity in the wireless communication system(1000), when the UE (100) was in the ATTEMPTING TO UPDATE MM servicestate, and receives the valid TMSI in the TMSI reallocation procedurewhen the RRC connection exists, according to some example embodiments;and

FIG. 5 is an example sequence flow diagram illustrating operations forhandling the call connectivity in the wireless communication system(1000), when the UE (100) was in the ATTEMPTING TO UPDATE MM servicestate, and receives the Paging message with IMSI when the timer T3211,T3213, and/or T3246 is running, according to some example embodiments.

DETAILED DESCRIPTION

Some example embodiments herein and the various features andadvantageous details thereof are explained more fully with reference tothe non-limiting examples that are illustrated in the accompanyingdrawings and detailed in the following description. Descriptions ofwell-known components and processing techniques may be omitted so as tonot unnecessarily obscure the embodiments herein. Also, some exampleembodiments described herein are not necessarily mutually exclusive, assome example embodiments may be combined with one or more other exampleembodiments to form new example embodiments. The term “or” as usedherein, refers to a non-exclusive or, unless otherwise indicated. Theexamples used herein are intended merely to facilitate an understandingof ways in which some example embodiments herein may be practiced and tofurther enable those skilled in the art to practice some exampleembodiments. Accordingly, the examples should not be construed aslimiting the scope of some example embodiments.

As is traditional in the field, some example embodiments may bedescribed and illustrated in terms of blocks which carry out a describedfunction or functions. These blocks, which may be referred to herein asunits or modules or the like, may be physically implemented byprocessing circuitry. The term ‘processing circuitry,’ as used in thepresent disclosure, may refer to, for example, hardware including logiccircuits; a hardware/software combination such as a processor executingsoftware; or a combination thereof. For example, the processingcircuitry more specifically may include, but is not limited to, acentral processing unit (CPU), an arithmetic logic unit (ALU), a digitalsignal processor, a microcomputer, a field programmable gate array(FPGA), a System-on-Chip (SoC), a programmable logic unit, amicroprocessor, application-specific integrated circuit (ASIC), etc.Accordingly, the blocks may be physically implemented by analog and/ordigital circuits such as logic gates, integrated circuits,microprocessors, microcontrollers, memory circuits, passive electroniccomponents, active electronic components, optical components, hardwiredcircuits, and/or the like, and/or may optionally be driven by firmwareand/or software. The circuits may, for example, be embodied in one ormore semiconductor chips, and/or on substrate supports such as printedcircuit boards and/or the like. The circuits constituting a block may beimplemented by dedicated hardware, or by a processor (e.g., one or moreprogrammed microprocessors and associated circuitry), or by acombination of dedicated hardware to perform some functions of the blockand a processor to perform other functions of the block. Each block ofsome example embodiments may be physically separated into two or moreinteracting and discrete blocks without departing from the scope of someexample embodiments. Likewise, the blocks of some example embodimentsmay be physically combined into more complex blocks without departingfrom the scope of some example embodiments.

The accompanying drawings are used to help easily understand varioustechnical features and it should be understood that some exampleembodiments presented herein are not limited by the accompanyingdrawings. As such, the present disclosure should be construed to extendto any alterations, equivalents and substitutes in addition to thosewhich are particularly set out in the accompanying drawings. Althoughthe terms first, second, etc. may be used herein to describe variouselements, these elements should not be limited by these terms. Theseterms are generally only used to distinguish one element from another.

According to some example embodiments, when a UE responds to a receivedpaging message including an IMSI, a paging response message is triggeredand a T3211 timer (which is running) stops. A Radio Resource Control(RRC) connection is established with a base station for performing TMSIRE-ALLOCATION. For example, the UE receives a new TMSI from the basestation and stores the new TMSI. In some example embodiments, the UE mayreceive a TMSI reallocation command from the base station and send aTMSI reallocation complete message to the base station in response.Connection management (CM) layer procedures corresponding to thereceived paging message are completed and connection (e.g., a RadioResource Control (RRC) connection with a base station) release isperformed. While the MM Service state of the UE remains in an ATTEMPTINGTO UPDATE state, the UE waits for T3212 expiry or the UE waits forchange of location area (LA) to trigger the location update procedure tothe base station.

When a conventional UE subsequently receives a paging message includingthe new TMSI received during the TMSI RE-ALLOCATION, the conventional UEdoes not respond to the paging message because the MM Service state ofthe conventional UE remains in the ATTEMPTING TO UPDATE state. Byfailing to respond to the paging message, the conventional UE misses anassociated service communication. For example, the conventional UE maymiss a circuit switched (CS) call, a CS short message service (SMS)message and/or CS supplementary service (SS) information.

Also, the conventional UE remains in the ATTEMPTING TO UPDATE MM Servicestate until the T3212 timer expires, or the location area (LA) of theconventional UE changes (e.g., due to the T3211 timer being stopped whenthe TMSI RE-ALLOCATION is performed). Accordingly, the conventional UEremains in the ATTEMPTING TO UPDATE MM Service state for an excessivelylong period during which the IMSI of the conventional UE is exposed(e.g., with each paging message sent by the base station) to other UEshaving the same Discontinuous Reception (DRX) cycle or a similar DRXcycle.

Excerpts from 3GPP TS 24.008: Service State, ATTEMPTING TO UPDATE

When in state MM IDLE and service state ATTEMPTING TO UPDATE the mobilestation:

-   -   responds to paging (e.g., paging messages including an IMSI);        and

Timers of Mobility Management Indicated in Table 1

TABLE 1 TIME TIMER MM OUT CAUSE FOR NORMAL AT THE NUM. STATE VAL. STARTSTOP EXPIRY T3211 MM 15 s LOCATION cell change Restart the IDLE,UPDATING request for location REJECT with MM updating other causeestablishment procedure. values as change of LA described in section4.4.4.9 lower layer failure or RRC connection released after RRCconnection abort during location updating procedure

Accordingly, some example embodiments herein achieve a method forhandling a service connectivity (e.g., service connection) in a wirelesscommunication system. The method includes detecting, by a UE, that theUE is in the ATTEMPTING TO UPDATE MM service state. Further, the methodincludes receiving, by the UE, a valid TMSI in a TMSI reallocationprocedure while the UE is connected to a base station over a RRCconnection. Further, the method includes changing, by the UE, the MMservice state to a NORMAL SERVICE state based on the TMSI reallocationprocedure. Further, the method includes changing, by the UE, an updatestatus to U1 UPDATED.

Some example embodiments provide operations performed in the context ofthe 3GPP 24.008 standard.

In some example embodiments, upon receipt of a TMSI REALLOCATION COMMANDmessage, the UE stores the Location Area Identifier (LAI) in aSubscriber Identity Module (SIM)/Universal SIM (USIM). If the receivedidentity is the IMSI of the relevant UE, the UE deletes any TMSI. If thereceived identity is a TMSI, the UE stores the TMSI in the SIM/USIM. Inboth cases the UE sends a TMSI REALLOCATION COMPLETE message to the basestation.

In some example embodiments, if the UE was in ATTEMPTING TO UPDATE andthe UE received a valid TMSI, the UE may set the service state to NORMALSERVICE and the update status to U1 UPDATED.

The U1 UPDATED update status indicates the last location updatingattempt was successful (e.g., the procedure outcome was correct and theanswer was acceptance from the base station). With this update status,the SIM/USIM also contains the LAI of the LA where the subscriber isregistered, and possibly a valid TMSI, GSM ciphering key, a UMTSintegrity key, a UMTS ciphering key and/or a ciphering key sequencenumber. Furthermore, if the UE supports an A5 ciphering technique usinga 128-bit ciphering key and a USIM is in use, then the UE may contain avalid GSM Kc128. The “Location update status” stored on the SIM/USIM maybe “updated”.

In some example embodiments, if the T3211, T3213 and/or T3246 timer wasrunning, the UE may perform the location updating procedure on RRCconnection release provided TMSI reallocation was not performed during apaging procedure.

In some example embodiments, when the UE was in the ATTEMPTING TO UPDATEMM service state, and if the UE receives a valid TMSI in a TMSIreallocation procedure (e.g., when an RRC connection with the basestation exists), then the UE may change the MM service state to NORMALSERVICE and also change the Update status to U1 UPDATED.

In some example embodiments, when the UE was in the ATTEMPTING TO UPDATEMM service state, and if the UE receives the paging message with an IMSIwhen the timer T3211, T3213, and/or T3246 is running, then the UE mayperform a location updating procedure on RRC connection release provideda TMSI reallocation procedure was not performed when RRC connection wasavailable.

Some example embodiments provide an improved UE that may reduce the missof paging (with TMSI) when the previous paging (with IMSI) wassuccessfully responded and the service was established properly.

Referring now to the drawings, and more particularly to FIGS. 1a through5, there are shown some example embodiments.

FIG. 1a illustrates an overview of a wireless communication system(1000) for handling service connectivity, according to some exampleembodiments. In some example embodiments, the service connectivity is atleast one of a call connectivity, a Short Message Service (SMS)connectivity and/or a supplementary service (SS) connectivity.

In some example embodiments, the wireless communication system (1000)includes a UE (100) and/or a base station (200). The UE (100) may be butis not limited to, for example, a cellular phone, a tablet, a smartphone, a laptop, a Personal Digital Assistant (PDA), a globalpositioning system device, a multimedia device, a video device, aninternet of things (IoT) device, a smart watch, a game console, anUnmanned Aerial Vehicle (UAV), an airplane, and/or the like. The UE(100) may also be referred to by those skilled in the art as a mobilestation, a subscriber station, a mobile unit, a subscriber unit, awireless unit, a remote unit, a mobile device, a wireless device, awireless communications device, a mobile subscriber station, an accessterminal, a mobile terminal, a wireless terminal, a remote terminal, ahandset, a user agent, a mobile client, and/or the like. The basestation (200) may also be referred to as a base transceiver station, aradio base station, a radio transceiver, a transceiver function, a basicservice set (BSS), an extended service set (ESS), an eNodeB (eNB), agNodeB (gNB), and/or the like.

In some example embodiments, the UE (100) may detect (e.g., determine)that the UE (100) is in a ATTEMPTING TO UPDATE MM service state andreceive a valid TMSI in a TMSI reallocation procedure when the UE (100)is connected to the base station (200) via a RRC connection. Further,the UE (100) may change the MM service state to NORMAL SERVICE (e.g.,from the ATTEMPTING TO UPDATE) based on the TMSI reallocation procedureand change an update status to U1 UPDATED.

Further, the UE (100) may receive a paging indication message from thebase station (200) and/or send a paging response message to the basestation (200) to establish the service based on the paging indicationmessage. According to some example embodiments, the service may be atleast one of a CS call, a Short Message Service (SMS) message and/orsupplementary service (SS) information.

In some example embodiments, the UE (100) may detect (e.g., determine)that the UE (100) is in the ATTEMPTING TO UPDATE MM service state andreceive the paging message (e.g., the paging indication message) withthe IMSI. Further, the UE (100) may determine whether or not a timer isrunning and/or perform a location updating procedure on the RRCconnection release to indicate that the TMSI reallocation procedure isnot performed with the base station (200) in response to receiving thepaging message with the IMSI when the timer is running. The exampledetailed operations of handling the call connectivity are explainedbelow in association with FIGS. 4 and 5.

FIG. 1b illustrates various hardware components of the UE (100),according to some example embodiments. The UE (100) may include aprocessor (110), a communicator (120), a memory (130) and/or a timer(140). The timer (140) may be a T3211, T3213, T3246 and/or the like.According to some example embodiments, operations described herein asbeing performed by the UE (100), the processor (110), the communicator(120) and/or the timer (140) may be performed by processing circuitry.The processor (110) may be coupled with the communicator (120), thememory (130) and/or the timer (140). The processor (110) may detect(e.g., determine) that the UE (100) is in the ATTEMPTING TO UPDATE MMservice state and receive the valid TMSI in the TMSI reallocationprocedure when the UE (100) is connected to the base station (200) viathe RRC connection. Further, the processor (110) may change the MMservice state to the NORMAL SERVICE state based on the TMSI reallocationprocedure and change the update status to U1 UPDATED.

Further, the processor (110) may receive the paging indication messagefrom the base station (200) and/or send the paging response message tothe base station (200) to establish the service based on the pagingindication message.

In some example embodiments, the processor (110) may detect (e.g.,determine) that the UE (100) is in the ATTEMPTING TO UPDATE MM servicestate and receive the paging message with the IMSI. Further, theprocessor (110) may determine whether the timer (140) is running and/orperform a location updating procedure on the RRC connection release toindicate that the TMSI reallocation procedure is not performed with thebase station (200) in response to receiving the paging message with theIMSI when the timer (140) is running.

Further, the communicator (120) may perform communication internallybetween internal hardware components and/or with external devices viaone or more networks. The memory (130) may store instructions to beexecuted by the processor (110). The memory (130) may includenon-volatile storage elements. Examples of such non-volatile storageelements may include magnetic hard discs, optical discs, floppy discs,flash memories, and/or forms of electrically programmable memories(EPROM) and/or electrically erasable and programmable (EEPROM) memories.In addition, the memory (130) may, in some examples, be considered anon-transitory storage medium. The term “non-transitory” may indicatethat the storage medium is not embodied in a carrier wave or apropagated signal. However, the term “non-transitory” should not beinterpreted that the memory (130) is non-movable. In some examples, thememory (130) may store larger amounts of information than the memory. Incertain examples, a non-transitory storage medium may store data thatmay, over time, change (e.g., in Random Access Memory (RAM) or cache).

Although the FIG. 1b shows various hardware components of the UE (100)but it is to be understood that some example embodiments are not limitedthereon. In some example embodiments, the UE (100) may include less ormore of the various hardware components. Further, the labels or names ofthe components are used only for illustrative purpose and does not limitthe scope of some example embodiments. One or more components may becombined together to perform the same function or a substantiallysimilar function to handle the call connectivity in the wirelesscommunication system (1000).

FIG. 1c illustrates various hardware components of the processor (110),according to some example embodiments. In some example embodiments, theprocessor (110) includes a UE state determiner (110 a), a TMSIreallocation procedure controller (110 b), a UE state updater (110 c)and/or a paging message handler (110 d). According to some exampleembodiments, operations described herein as being performed by the UEstate determiner (110 a), the TMSI reallocation procedure controller(110 b), the UE state updater (110 c) and/or the paging message handler(110 d) may be performed by processing circuitry.

The UE state determiner (110 a) may detect (e.g., determine) that the UE(100) is in the ATTEMPTING TO UPDATE MM service state. The TMSIreallocation procedure controller (110 b) may receive the valid TMSI inthe TMSI reallocation procedure when the UE (100) is connected to thebase station (200) via the RRC connection. Further, the UE state updater(110 c) may change the MM service state to the NORMAL SERVICE statebased on the TMSI reallocation procedure and/or change the updatedstatus to U1 UPDATED.

Further, the paging message handler (110 d) may receive the pagingindication message from the base station (200) and/or send the pagingresponse message to the base station (200) to establish the servicebased on the paging indication message.

In some example embodiments, the UE state determiner (110 a) may detect(e.g., determine) that the UE (100) is in the ATTEMPTING TO UPDATE MMservice state. The paging message handler (110 d) may receive the pagingmessage with the IMSI. Further, the UE state updater (110 c) maydetermine whether the timer (140) is running and/or perform a locationupdating procedure on the RRC connection release to indicate that theTMSI reallocation procedure is not performed with the base station (200)in response to receiving the paging message with the IMSI when the timer(140) is running.

Although the FIG. 1b shows various hardware components of the processor(110) but it is to be understood that some example embodiments are notlimited thereon. In some example embodiments, the processor (110) mayinclude less or more of the various hardware components. Further, thelabels or names of the components are used only for illustrative purposeand does not limit the scope of some example embodiments. One or morecomponents may be combined together to perform the same function or asubstantially similar function to handle the call connectivity in thewireless communication system (1000).

FIG. 2 is a flow diagram (400) illustrating a method for handlingservice connectivity in the wireless communication system (1000), whenthe UE (100) was in the ATTEMPTING TO UPDATE MM service state, receivesthe valid TMSI in the TMSI reallocation procedure when the RRCconnection exists, according to some example embodiments. The operations(402-412) may be performed by processing circuitry (e.g., the processor(110)).

At operation 402, the method includes detecting (e.g., determine) thatthe UE (100) is in the ATTEMPTING TO UPDATE MM service state. Forexample, the UE (100) may store an MM service state parameter (e.g., inthe memory 130) and may update the value of the MM service stateparameter upon each change in the MM service state. According to someexample embodiments, the UE (100) may determine that the UE (100) is inthe ATTEMPTING TO UPDATE MM service state by reading the value of the MMservice state parameter. At operation 404, the method includes receivingthe valid TMSI in the TMSI reallocation procedure when the UE (100) isconnected to the base station (200) via the RRC connection. For example,the TMSI (e.g., the TMSI of the UE (100)) may be received from the basestation (200) and may be valid in that the TMSI corresponds to a currentlocation area (LA) of the UE (100). At operation 406, the methodincludes changing the MM service state to the NORMAL SERVICE state basedon the TMSI reallocation procedure. According to some exampleembodiment, the UE (100) may change the MM service state to the NORMALSERVICE state in response to receiving the valid TMSI and/or in responseto determining the UE (100) is in the ATTEMPTING TO UPDATE MM servicestate, and may update the MM service state parameter accordingly. Atoperation 408, the method includes changing the update status to U1UPDATED (e.g., in response to in response to one or more of receivingthe valid TMSI, determining the UE (100) is in the ATTEMPTING TO UPDATEMM service state, and/or changing the MM service state to the NORMALSERVICE state). For example, the UE (100) may store an update statusparameter (e.g., in the memory 130) and may update the value of theupdate status parameter upon each change in the update status. Atoperation 410, the method includes receiving the paging indicationmessage from the base station (200). For example, the UE (100) mayreceive a paging indication message including the valid TMSI. Atoperation 412, the method includes sending the paging response messageto the base station (200) to establish the service. Accordingly, someexample embodiments provide an improved UE that responds to the pagingmessages to which the conventional UEs fail to respond. In particular,by changing the MM service state to the NORMAL SERVICE state, and/orchanging the update status to U1 UPDATED, the improved UE responds tothe received paging indication message including the TMSI. Therefore,the improved UE receives the incoming service communication associatedwith the received paging indication (e.g., the circuit switched (CS)call, the CS short message service (SMS) message and/or the CSsupplementary service (SS) information) missed by the conventional UEs.

FIG. 3 is a flow diagram (500) illustrating a method for handling theservice connectivity in the wireless communication system (1000), whenthe UE (100) was in the ATTEMPTING TO UPDATE MM service state, receivesthe Paging message with IMSI when the timer T3211, T3213, and/or T3246is running, according to some example embodiments. The operations(502-508) may be performed by processing circuitry (e.g., the processor(110)).

At operation 502, the method includes detecting (e.g., determining) thatthe UE (100) is in the ATTEMPTING TO UPDATE MM service state. Forexample, the UE (100) may store an MM service state parameter (e.g., inthe memory 130) and may update the value of the MM service stateparameter upon each change in the MM service state. According to someexample embodiments, the UE (100) may determine that the UE (100) is inthe ATTEMPTING TO UPDATE MM service state by reading the value of the MMservice state parameter. At operation 504, the method includes receivinga paging message (e.g., a paging indication message) including an IMSIof the UE (100). According to some example embodiments, the UE (100) maystop the T3211 timer in response to receiving the paging message inoperation 504. At operation 506, the method includes determining whetherthe timer (140) (e.g., the T3212 timer) is running. According to someexample embodiments, the timer (140) may be a timer parameter stored atthe UE (100) (e.g., in the memory 130) indicating whether the timer(140) is running. The UE (100) may determine whether the timer (140) isrunning by reading the value of the timer parameter. At operation 508,the method includes performing the location area updating (LAU)procedure on the RRC connection release to indicate that the TMSIreallocation procedure is not performed with the base station 200 inresponse to receiving the paging message with the IMSI when the timer(140) is running. According to some example embodiments, the UE (100)may perform the LAU procedure immediately or promptly after a servicecommunication associated with the paging indication message is completedbased on a criterion. According to some example embodiments, thecriterion may include the UE (100) determining that the T3212 timer isrunning after the service communication associated with the pagingindication message is completed. According to some example embodiments,the criterion may include the UE (100) determining that the MM servicingstate is still set to ATTEMPTING TO UPDATE after the servicecommunication associated with the paging indication message iscompleted. According to some example embodiments, the LAU procedurewould be performed according to one or more methods known to a personhaving ordinary skill in the art. Accordingly, some example embodimentsprovide an improved UE avoid or reduce the excessively long periodsduring which the conventional UEs remain in the ATTEMPTING TO UPDATE MMService state. For example, the improved UE may perform the LAUprocedure immediately or promptly after a service communicationassociated with the paging indication message is completed based on acriterion. Therefore, the improved UE reduces period during which theIMSI of the UE is exposed, thereby improving the security of the IMSI ofthe UE.

The various actions, acts, blocks, operations, or the like in the flowdiagrams (400 and 500) may be performed in the order presented, in adifferent order, or simultaneously or contemporaneously. Further, insome example embodiments, some of the actions, acts, blocks, operations,or the like may be omitted, added, modified, skipped, or the likewithout departing from the scope of some example embodiments.

FIG. 4 is an example sequence flow diagram illustrating operations forhandling the call connectivity in the wireless communication system(1000), when the UE (100) was in the ATTEMPTING TO UPDATE MM servicestate, and receives the valid TMSI in the TMSI reallocation procedurewhen the RRC connection exists, according to some example embodiments.

At operation S602, the UE (100) may be successfully registered in theLAI-A and the UE (100) has the valid TMSI (e.g., a TMSI associated withthe UE (100) and the LAI-A). At operation S604, the UE (100) may move tothe LAI-B. At operation S606, the UE (100) may send the location updaterequest message with the TMSI to the base station (200). At operationS608, the base station (200) may send the location update reject messageto the UE (100) based on the network failure cause value #7. Atoperation S610, the UE (100) may detect that the TMSI and the MM servicestate is set to ATTEMPTING TO UPDATE (e.g., as a result of operationsS604-S608). For example, the UE (100) may detect (e.g., determine) thatthe TMSI is invalid and that the MM service state is set to ATTEMPTINGTO UPDATE. At operation S612, the UE (100) may detect that the T3211timer is running. At operation S614, the UE (100) may receive the pagingindication with an IMSI (e.g., an IMSI of the UE (100)) from the basestation (200).

At operation S616, the UE (100) may stop the T3211 timer. At operationS618, the UE (100) may send the paging response to the base station(200). At operation S620, the UE (100) may receive the TMSI reallocationcommand from the base station (200). For example, the TMSI reallocationcommand may include a valid TMSI associated with the UE (100) and theLAI-B. At operation S622, the UE (100) may send the TMSI reallocationcomplete (e.g., an indication of successful TMSI reallocation) to thebase station (200). At operation S624, a CS call may be established(e.g., a service communication associated with the paging indicationmessage received in operation S612) successfully between the UE (100)and the base station (200). At operation S626, the user of the UE (100)may be disconnected from the call (e.g., the user may disconnect thecall, for example, when the call is completed) and the UE (100) may bemoved to the IDLE state (e.g., a call status may be set to the IDLEstate).

At operation S628, the UE (100) may set the MM servicing state to NORMALas valid TMSI is received (e.g., in response to receiving a valid TMSIduring the TMSI reallocation and/or the service communication associatedwith the paging indication message terminating). At operation S630, theUE (100) may receive the paging information with the TMSI. For example,the UE (100) may receive a paging indication message including the validTMSI associated with the UE (100) and the LAI-B. At operation S632, theUE (100) may respond to the paging message because the MM service stateis NORMAL SERVICE. For example, at S632, the UE (100) may determine thata paging response should be sent because the MM service state is set toNORMAL SERVICE. At operation S634, the UE (100) may send the pagingresponse to the base station (200). At operation S636, further, a callassociated with the paging indication message including the valid TMSImay be established successfully between the UE (100) and the basestation (200).

In some example embodiments, when the UE (100) was in the ATTEMPTING TOUPDATE MM service state, and if the UE (100) receives the valid TMSI inthe TMSI reallocation procedure (when the RRC connection exists), thenthe UE (100) may change the MM service state to NORMAL SERVICE and mayalso change the update status to U1 UPDATED.

FIG. 5 is an example sequence flow diagram illustrating operations forhandling the call connectivity in the wireless communication system(1000), when the UE (100) is in the ATTEMPTING TO UPDATE MM servicestate, and receives the Paging message with IMSI when the timer T3211,T3213, and/or T3246 is running, according to some example embodiments.

At operation S702, the UE (100) may be successfully registered in theLAI-A and the UE (100) may have the valid TMSI (e.g., a TMSI associatedwith the UE (100) and the LAI-A). At operation S704, the UE (100) maymove to the LAI-B. At operation S706, the UE (100) may send the locationupdate request message with the TMSI to the base station (200). Atoperation S708, the base station (200) may send the location updatereject message to the UE (100) based on the network failure cause value#7. At operation S710, the UE (100) may detect that the TMSI and theATTEMPTING TO UPDATE MM service state is set (e.g., as a result ofoperations S704-S708). For example, the UE (100) may detect (e.g.,determine) that the TMSI is invalid and that the MM service state is setto ATTEMPTING TO UPDATE. At operation S712, the UE (100) may detect thatthe T3211 timer is running. At operation S714, the UE (100) may receivea paging indication message including an IMSI (e.g., the IMSI of the UE(100)) from the base station (200). At operation S716, the UE (100) maystop the T3211 timer. At operation S718, the UE (100) may send thepaging response to the base station (200).

At operation S720, a CS call may be established (e.g., a servicecommunication associated with the paging indication message received inoperation S714) successfully between the UE (100) and the base station(200). At operation S722, the user of the UE (100) may be disconnectedfrom the call (e.g., the user may disconnect the call, for example, whenthe call is completed) and the UE (100) may move to the IDLE state(e.g., a call status may be set to the IDLE state). At operation S724,the UE (100) may detect that the MM servicing state is still set toATTEMPTING TO UPDATE and may perform the location area updating (LAU)process immediately or promptly. At operation S726, the UE (100) maysend the location updating request with the IMSI to the base station(200). At operation S728, the UE (100) may receive the location updateaccept including the TMSI (e.g., a valid TMSI associated with the UE(100) and the LAI-B) from the base station (200). At operation S730, ifthe LAU is successful then the UE (100) may be in NORMAL SERVICE MMservicing state and updated. Further, the paging (e.g., subsequentpaging indication messages and corresponding service communications) maybe handled normally (e.g., using the valid TMSI associated with the UE(100) and the LAI-B). According to some example embodiments, the UE(100) may establish a service using the valid TMSI (e.g., via pagingmessages). According to some example embodiments, the service may be atleast one of a CS call, a Short Message Service (SMS) message and/orsupplementary service (SS) information.

In some example embodiments, when the UE (100) is in the ATTEMPTING TOUPDATE MM service state, the UE (100) receives the paging message withIMSI, and at that time the T3211, T3213, and/or T3246 timer was running,then the UE (100) may perform location updating procedure on RRCConnection release, provided TMSI reallocation procedure was notperformed when the RRC connection was available.

The above examples are provided in the context of the call service. Theperson having ordinary skill in the art would understand that the aboveexamples are likewise applicable in the contexts of SMS and/or SS.

Some example embodiments disclosed herein may be implemented usingprocessing circuitry. For example, some example embodiments may beimplemented using at least one software program running on at least onehardware device and performing network management functions to controlthe elements.

The various operations of methods described above may be performed byany suitable device capable of performing the operations, such asprocessing circuitry. For example, the operations of methods describedabove may be performed by various hardware and/or software implementedin some form of hardware (e.g., processor, ASIC, etc.).

The software may comprise an ordered listing of executable instructionsfor implementing logical functions, and may be embodied in any“processor-readable medium” for use by or in connection with aninstruction execution system, apparatus, or device, such as a single ormultiple-core processor or processor-containing system.

The blocks or operations of a method or algorithm and functionsdescribed in connection with some example embodiments disclosed hereinmay be embodied directly in hardware, in a software module executed by aprocessor, or in a combination of the two. If implemented in software,the functions may be stored on or transmitted over as one or moreinstructions or code on a tangible, non-transitory computer-readablemedium. A software module may reside in Random Access Memory (RAM),flash memory, Read Only Memory (ROM), Electrically Programmable ROM(EPROM), Electrically Erasable Programmable ROM (EEPROM), registers,hard disk, a removable disk, a CD ROM, or any other form of storagemedium known in the art.

The foregoing description of the some example embodiments will so fullyreveal the general nature of the example embodiments that others can, byapplying current knowledge, readily modify and/or adapt for variousapplications some example embodiments without departing from the genericconcept, and, therefore, such adaptations and modifications should andare intended to be comprehended within the meaning and range ofequivalents of some example embodiments. It is to be understood that thephraseology or terminology employed herein is for the purpose ofdescription and not of limitation. Therefore, while some exampleembodiments herein have been described, those skilled in the art willrecognize that some example embodiments can be practiced withmodification within the spirit and scope of some example embodiments asdescribed herein.

What is claimed is:
 1. A method for handling a service connection in awireless communication system, comprising: detecting, by a UserEquipment (UE), a Mobility Management (MM) service state of the UE isset to ATTEMPTING TO UPDATE; receiving, by the UE, a paging messageincluding an International Mobile Subscriber Identity (IMSI);determining, by the UE, whether a timer is running; performing, by theUE, a first location area updating procedure with a base station inresponse to the detecting a MM service state, the determining the timeris running, and releasing a Radio Resource Control (RRC) connection withthe base station associated with the paging message; and establishingthe service connection with the base station using a valid TemporaryMobile Subscriber Identity (TMSI) obtained during the first locationarea updating procedure.
 2. The method of claim 1, wherein the serviceconnection is at least one of a call connection, a Short Message Service(SMS) connection or a supplementary service (SS) connection.
 3. Themethod of claim 1, wherein the valid TMSI is associated with a currentlocation area of the UE.
 4. The method of claim 1, wherein the MobilityManagement (MM) service state of the UE is set to ATTEMPTING TO UPDATEbased on a failed second location area updating procedure with the basestation.
 5. The method of claim 1, wherein the receiving the pagingmessage is performed after the detecting the MM service state is set toATTEMPTING TO UPDATE and before the performing the first location areaupdating procedure.
 6. The method of claim 1, wherein the first locationarea updating procedure comprises: sending the IMSI to the base station;and receiving the valid TMSI from the base station.
 7. The method ofclaim 1, further comprising: changing the MM service state to a NORMALSERVICE state in response to successful completion of the first locationarea updating procedure.
 8. The method of claim 1, further comprising:starting another timer corresponding to the MM service state of the UEbeing set to ATTEMPTING TO UPDATE, the other timer having an expirytime; and stopping the other timer before the other timer reaches theexpiry time in response to the receiving the paging message, wherein theestablishing the service connection is performed while the other timerremains stopped before reaching the expiry time.
 9. A User Equipment(UE) for handling a service connection in a wireless communicationsystem, comprising: processing circuitry configured to, detect aMobility Management (MM) service state of the UE is set to ATTEMPTING TOUPDATE, receive a paging message including an International MobileSubscriber Identity (IMSI), determine whether a timer is running,perform a first location area updating procedure with a base station inresponse to detecting the MM service state is set to ATTEMPTING TOUPDATE, determining the timer is running, and releasing a Radio ResourceControl (RRC) connection with the base station associated with thepaging message, and establish the service connection with the basestation using a valid Temporary Mobile Subscriber Identity (TMSI)obtained during the first location area updating procedure.
 10. The UEof claim 9, wherein the service connection is at least one of a callconnection, a Short Message Service (SMS) connection or a supplementaryservice (SS) connection.
 11. The UE of claim 9, wherein the valid TMSIis associated with a current location area of the UE.
 12. The UE ofclaim 9, wherein the Mobility Management (MM) service state of the UE isset to ATTEMPTING TO UPDATE based on a failed second location areaupdating procedure with the base station.
 13. The UE of claim 9, whereinthe paging message is received after the MM service state is detected asbeing set to ATTEMPTING TO UPDATE and before the first location areaupdating procedure is performed.
 14. The UE of claim 9, wherein thefirst location area updating procedure comprises: sending the IMSI tothe base station; and receiving the valid TMSI from the base station.15. The UE of claim 9, wherein the processing circuitry is configuredto: change the MM service state to a NORMAL SERVICE state in response tosuccessful completion of the first location area updating procedure. 16.The UE of claim 9, wherein the processing circuitry is configured to:start another timer corresponding to the MM service state of the UEbeing set to ATTEMPTING TO UPDATE, the other timer having an expirytime; and stop the other timer before the other timer reaches the expirytime in response to receiving the paging message, wherein the serviceconnection is established while the other timer remains stopped beforereaching the expiry time.
 17. A non-transitory computer-readable mediumstoring instructions that, when executed by at least one processor,cause the at least one processor to: detect a Mobility Management (MM)service state of a UE is set to ATTEMPTING TO UPDATE; receive a pagingmessage including an International Mobile Subscriber Identity (IMSI);determine whether a timer is running; perform a first location areaupdating procedure with a base station in response to detecting the MMservice state is set to ATTEMPTING TO UPDATE, determining the timer isrunning, and releasing a Radio Resource Control (RRC) connection withthe base station associated with the paging message; and establish theservice connection with the base station using a valid Temporary MobileSubscriber Identity (TMSI) obtained during the first location areaupdating procedure.
 18. The non-transitory computer-readable medium ofclaim 17, wherein the service connection is at least one of a callconnection, a Short Message Service (SMS) connection or a supplementaryservice (SS) connection.
 19. The non-transitory computer-readable mediumof claim 17, wherein the valid TMSI is associated with a currentlocation area of the UE.
 20. The non-transitory computer-readable mediumof claim 17, wherein the Mobility Management (MM) service state of theUE is set to ATTEMPTING TO UPDATE based on a failed second location areaupdating procedure with the base station.